This paper examines the effect of obtaining an ISO 9000 certification on various aspects of business performance using firm-level panel data from Slovenia covering the period 1987-2006. To control for the possible endogeneity of obtaining the certification propensity score matching is combined with a difference-in-differences approach. The results indicate that an ISO 9000 certification boost the certified firm's sales, exports and employment. It also has a positive effect on profits, profitability ratio, labor productivity and wages, though these effects appear with a delay and the latter two are less robust.
